1. Field of the Invention
The invention relates to a small electric motor.
2. Description of Related Art
Known small motors are constructed such that the shafts of the rotors are comprised of steel and have a substantially semi-spherical cap at the shaft end which runs against a contact surface. A disadvantage of such bearings is that the cap of the shaft end acts like a magnetic pole and attracts magnetic particles and, in this way, can damage the bearing location prematurely and finally destroy it. The magnetic pole results from the shaft being comprised of ferromagnetic material and the rotor containing a permanent magnet whose magnetic field closes across the shaft.
Such damaged bearing locations cause strong noises which are not permissible, in particular, in the case of small electric motors running, for example, in air-conditioning devices of motor vehicles.
It is an object of the invention to provide a bearing which does not have the aforementioned disadvantages.
The solution to this object resides in that the axial bearing comprises a non-magnetic ball which is arranged in a depression centrally provided within one end of the shaft and is guided by the rim of this depression and runs with its side facing away from the shaft against the running surface of a bushing, or in that a depression with a rim is provided at one end of the shaft and a non-magnetic ball is fastened in the depression, wherein the part of the ball projecting from the shaft end runs against a running surface of a bushing. Further details and advantageous developments of the invention result from the embodiments described in the following and illustrated in the drawing.
Further details and advantageous developments of the invention result from the embodiments described in the following and illustrated in the drawing as well as from the dependent claims.